Stirrup for pole climber



Jan. 10, 1967 c, LAWRENCE 3,297,105

STIRRUP FOR POLE CLIMBER Filed Aug. 30, 1965 ,L v w I\ \3' INVENTOR.

55 V Z 26 054/1456 a L/(WE'A/CE Unite States atent Patented Jan. 10, I967 3,297,105 STIRRIJP FDR PULE CLIMBER Delmer C. Lawrence, RED. 2, Bowling Road, Hope Township, Barry County, Mich. 48628 Filed Aug. 30, 1965, Ser. No. 483,628 4 Claims. (Cl. 18246) This invention relates in general to a pole climber and, more specifically, to a type thereof which is fabricated primarily from electrically nonconductive, and highly shock-resistant materials.

For many years, users and manufacturers of pole climbing equipment, such as pole climbers, have been keenly aware of the risks taken and the casualties which have been suffered by men who have used the previously available pole climbers. The casualties have, in general, developed from two sources. In the first place, most if not all of the existing pole climbers have large amounts of metal therein which are in contact or closely adjacent to or unins-ulated from the leg and/or foot of the person using the climber. Thus, if this metallic part accidentally touches a current carrying line of relatively high voltage, the user is almost always injured and is ofter electrocuted.

In the second place, most of the existing pole climbers are fabricated from materials which fatique after indeterminate, often relatively short, periods of use. Accordingly, it is necessary to replace frequently the pole climbers in order to avoid a casualty. However, as a practical matter, it has been found that some users of these climbers will either forget or neglect to replace them.

before the safe period of use has been exceeded and, as a result, the climber will fail under load and the user Will be injured.

Accordingly, the objects of this invention have been:

(1) To provide a pole climber which com-prises a minimum of metallic parts and which completely electrically insulates the user from such metal parts as are used.

(2) To provide a climber, as aforesaid, which is fabricated from a type of material capable of resisting fatigue for long periods of use which exceed the corresponding periods of use in most of the existing pole climbers.

(3) To provide a climber, as aforesaid, which is comfortable to wear, relatively light in weight, capable of giving the user a feeling of security, and capable of giving far better foot support than previously available in any existing pole climber.

Other objects and purposes of this invention will become apparent to persons familiar with this type of equipment upon reading the following specification and examining the accompanying drawings, in which:

FIGURE 1 is a side elevational view of said pole climber embodying the invention, and it may be either the front side or rear side depending upon which leg it is used.

FIGURE 2 is an edge elevational view of said pole climber.

FIGURE 3 is a sectional view taken along the line IIIIII in FIGURE 2.

FIGURE 4 is a sectional view taken along the line IVIV in FIGURE 1.

FIGURE 5 is a sectional view taken along the line V-V in FIGURE 1, and including a separable, foot-supporting member.

FIGURE 6 is a sectional view talcen along the line VI-VI in FIGURE 5.

FIGURE 7 is a sectional view taken along the line VII--V-II in FIGURE 1.

For convenience in description, the terms upper, lower and words of similar import will have reference to the pole climber as appearing in FIGURES 1 and 2.

The terms inner, outer and derivatives thereof will have reference to the geometric center of said pole climber and parts thereof.

General construction The objects and purposes of the invention, including those set forth above, have been met by providing a pole climber which is substantially L-shaped and fabricated primarily from a mixture of resin and fiberglass formed by a molding process. A metallic spur is attached to the L-shaped stirrup so that it is completely insulated from the user of the climber, and only a minimum of the metal is exposed to external contact. Strap and buckle means are provided for attaching the stirrup to the foot and leg of the user and the leg-engaging strap is mounted upon an adjustable bracket to fit the stirrup to the user. The invention also contemplates the use of a relatively fiat and elongated foot-engaging member which mounts upon the stirrup adjacent the spur.

Detailed description The pole climber 10'(FIGURES l and 2), which illustrates a preferred embodiment of the invention, is comprised of a substantially L-shaped stirrup 11 and an irregularly shaped gaff member 12. A strap-supporting bracket 13 is adjustably mounted upon the upright elemeat 14 of the stirrup I1 and strap-engaging buckle means 17 is mounted upon the free end of the horizontal element 18 of said stirrup 11.

The stirrup 11 is preferably fabricated from resin impregnated fiberglass ro-vings wherein the :glass rovings comprise approximately 40 percent of the total weight of the stirrup. In one preferred embodiment, the resin is a polyester resin in which the polyester solids comprise approximately percent of the weight of the resin. It has been found that a highly satisfactory resin consistency is provided where the resin has a relative fast cure characteristic and has a fast fiber wetting characteristic. The EPO to gel time is preferably in the order of three or four minutes.

In producing the resin mixture for the molded stirrup, the polyester resin is combined with a calcium carbonate filler and a catalyst which preferably is benzoyl peroxide.

In a typical mixture, the resin is catalyzed with from .75 to 1.25 weight percent of :benzoyl peroxide. In said typical mixture, the tiller comprises approximately 35 to 40 weight percent of the total resin mixture, including the polyester resin.

The combined plastic, filler and glass rovings are prepared for molding by placing the glass rovings together and drawing them through the resin mixture after which they are wound to form a bundle generally similar to the shape of the stirrup. The resin impregnated glass bundle is then placed in a heated mold which is closed and heated until the resin impregnated glass is cured, after which the cured resin is removed from the mold.

In a preferred embodiment of the invention, the upright element 14 has a substantially T-shaped cross section with the stem 21 projecting outwardly away from the users leg 22. This stem not only rigidifies the upright element 14, but also provides a thin cross section through which a plurality of uniformly spaced openings 23 may be provided for reasons appearing ereinafter.

The horizontal element 18 and the adjacent portion of the upright element 14- (FIGURE 3) are provided with a continuous groove 24 in the lower and outer surfaces thereof for snug but removable reception of the mountin-g rod 26 of the gaff member 12. With the rod 26 in the groove 24, the spur 27, which is integral with the rod 26, projects downwardly and slightly outwardly from the stirrup 11 adjacent the intersection of the upright and horizontal elements thereof. By this means, it will be seen that no part of the gaff member 12 is either directly or indirectly engageable with any metallic part located adjacent the inner surfaces of the stirrup 11 where direct electrical contact can be effected with the wearer of the pole climber 10.

The gaff member 12 is held in its position in the groove 24 ;by a pair of pins 28 and 29 (FIGURE 3) which may be fabricate-d from metal, but are recessed into the stirrup, as shown in FIGURE 4 with respect to the pin 28, so that they cannot readily engage a metallic or electrically conductive object adjacent the outer surface of the climber. The pins 28 and 29 extend through corresponding openings in the opposite ends of. the mounting rod 26, such as the opening 32, shown in FIGURE 4 for the pin 28. A corresponding opening 33 is provided in the stirrup 11 for said pin 28. It will be seen in FIG- URES 2 and 4, particularly, that the mounting rod 26 preferably extends slightly below the lower surface of the horizontal element 18 where it will engage, and thereby protect the stirrup 11 against engagement with, hard flat surfaces, such as concrete walls and streets.

In this particular embodiment, the buckle means 17 is of a substantially conventional type having a pivot element 34 (FIGURE 4) which is snugly but rotatably received through an opening 36 in the horizontal element 18 adjacent its free end. Said pivot element 34 is spaced a substantial distance from the adjacent portion of the mounting rod 26 and is preferably completely surrounded by the material of the stirrup 11, as shown in FIGURES 3 and 4, in order to prevent the flow of electrical current between these two elements. A strap of any convenient, conventional type, such as the strap 37 shown in broken lines in FIGURE 1, may have one end thereof looped around the stirrup 11 and mounting rod 26 adjacent the spur 27 so that the other end thereof is engageable with and by the buckle means 17 in a substantially conventional manner. The strap 37 will extend over the instep of the user of the climber 10 in a conventional manner. The location of the opening 36 in the horizontal element 18 is such, as shown in FIGURE 3, that the adjacent end of the mounting rod 26 intersects the direction of force applied upon the horizontal element 18 when the strap 37 is tightly secured to the buckle means 17.

The bracket 13 (FIGURES 1 and 7) is comprised of a tubular member 41 which is slideably and nonrotatably supported upon the upright element 14 for movement lengthwise thereof along a substantial portion of the upright element near its upper end. The portion 42 of the tubular member 41, which extends around the stem 21, has at least one pair of openings 43 and 43A which are alignable with any one of the openings 23 in the stem 21. A pin 44, which is preferably made from metal, is slideably receivable through the openings 43 and 43A and any one of the openings 23 for positively holding the bracket 13 in a selected position upon the upright ele ment 14.

The portion 42 of the tubular member 41 includes an integral, outward projection 46 with a slot 47 therethrough which is elongated lengthwise of the element 14. A strap 48, which is shown in broken lines in FIGURE 1 and which may be of any convenient, conventional type, is inserted through the slot 47 and is provided with buckle means 51 for holding said strap in place around the leg 22 of the user of the pole climber 10. Thus, where the pin 44 is inserted through the openings 43 and 43A nearest the slot 47, the strap 48 also serves to prevent accidental dislodgement of the pin from its opening.

The invention also contemplates the use of a foot-supporting member or plate 55 (FIGURES and 6) which straddles the horizontal element 18 of the stirrup 11 and greatly increases the amount of supporting surface available for engagement with the lower surface 56 (FIG- URE 1) of the shoe 57 worn by the user of the pole climber. As shown in FIGURE 6, the sole or front portion 58 of the shoe 57 engages the front portion 61 of the foot plate 55, and the heel 62 is supported upon the downwardly offset rear portion 63 of said foot plate 55. The front end of the heel 62 abuts against a shoulder 65 created by the downward offset of the rear portion 63.

The foot plate is provided with a downwardly opening transverse slot 66 adjacent the shoulder into which the horizontal element 18 can be received for the purpose of positively positioning the foot plate 55 with respect to said stirrup.

The plate 55 is preferably arranged so that it is spaced upwardly slightly from a hard fiat surface when the mounting rod 26 is in contact with said surface. The foot plate 55 is preferably fabricated from an electrically, nonconductive and fracture-resistant material, such as hard polyvinylchloride. However, it could be fabricated from a metal plate which is then completely coated with an electrically insulating material, such as rubber or plastic.

The operation of the climber 10 is probably evident from the foregoing descriptive material. That is, the bracket 13, with its strap 48 attached thereto, is mounted in the proper position upon the upright element 14 of the stirrup 11. Where the foot plate 55 is used, it is then mounted upon the horizontal element 18 of the stirrup 11 and the user of the climber 10 then places his shoe 57 upon the plate 55 so that the heel engages the shoulder 65. The strap 37 is then connected to the buckle means 17 and the climber 10 is ready for use.

It will be noted that the climber 10 is completely reversible so that it can be used with equal ease upon either the left or right leg and foot of the user. The only adjustment required involves the placing of the foot plate 55 upon the horizontal element 18 so that said plate points in the right direction. As appearing in FIGURE 1, the climber 10 is attached to a right leg and foot. However, as disclosed in FIGURES 5 and 6, the foot plate 55 is mounted for engagement by a left leg and shoe.

If the spur 27 has become worn so that it should be replaced, removal thereof can be quickly and easily effected by removing the pins 28 and 29, removing the gaff member 12 and replacing same with another gaff member, after which the pins 28 and 29 are returned to their positions. It will be seen that the strap 37 will not create an obstruction, as it can be slid along the horizontal element 18 to a position adjacent the buckle means 17 where it Will not interfere with the removal of the gaff member 12.

Although a particular preferred embodiment of the invention has been disclosed above for illustrative purposes, it will be understood that variations or modifications of such disclosure, which do not depart from the scope of the appended claims, are fully contemplated.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A pole climber comprising:

an L-shaped, resin impregnated fiberglass stirrup having relatively long and short elements disposed at substantially right angles to each other;

means defining a groove in the outer surface of said short element and in the portion of the outer surface of said long element adjacent said short element;

a metal spur and an elongated metallic member rigidly secured to said spur, said metallic member being snugly disposed within said groove and said spur extending substantially parallel with said long element adjacent said short element;

means rigidly securing said elongated member said groove;

strap and buckle means engaged with said L-shaped member adjacent said spur and engaged with said short element adjacent the free end thereof for holding a foot snugly adjacent said short element;

within a strap-engaging bracket secured to said long element near the free end thereof, said bracket being adjustable lengthwise of said long element; and

strap means mounted upon said bracket for engaging and thereby holding the leg associated with said foot snugly adjacent to and substantially parallel with said long element.

2. The structure of claim 1, wherein said L shaped member is comprised of a cured mixture of polyester resin, calcium carbonate and glass fibers, said resin including approximately 70 percent by weight of polyester solids, and said glass fibers constituting from 35 to 45 percent by weight of the total weight of the cured mixture.

3. The structure of claim 1, wherein said bracket surrounds said long member and has a slot therein through which said strap extends; and

wherein said bracket and said long member have a plurality of alignable openings therethrough, and pin means extendable through the aligned openings in said bracket and said long member for positively preventing relative movement thereof.

4. A structure according to claim 1, including an elongated relatively fiat foot-supporting member disposed upon the inner surface of said short element for engagement by said foot, said flat member having a transversely offset portion near one end thereof for reception of the heel of a shoe and a groove between said offset portion and the other end of said fiat member into which said short element is received, said flat member extending substantially away from both sides of said short element.

References Cited by the Examiner UNITED STATES PATENTS 1,243,436 10/1917 Marshall 182-46 1,867,894 7/1932 Rush 182--46 2,284,190 5/1942 Evans 18246 2,570,001 lO/l951 McCammond 182-22l REINALDO P. MACHADO, Primary Examiner. 

1. A POLE CLIMBER COMPRISING: AN L-SHAPED, RESIN IMPREGNATED FIBERGLASS STIRRUP HAVING RELATIVELY LONG AND SHORT ELEMENTS DISPOSED AT SUBSTANTIALLY RIGHT ANGLES TO EACH OTHER; MEANS DEFINING A GROOVE IN THE OUTER SURFACE OF SAID SHORT ELEMENT AND IN THE PORTION OF THE OUTER SURFACE OF SAID LONG ELEMENT ADJACENT SAID SHORT ELEMENT; A METAL SPUR AND AN ELONGATED METALLIC MEMBER RIGIDLY SECURED TO SAID SPUR, SAID METALLIC MEMBER BEING SNUGLY DISPOSED WITHIN SAID GROOVE AND SAID SPUR EXTENDING SUBSTANTIALLY PARALLEL WITH SAID LONG ELEMENT ADJACENT SAID SHORT ELEMENT; MEANS RIGIDLY SECURING SAID ELONGATED MEMBER WITHIN SAID GROOVE; STRAP AND BUCKLE MEANS ENGAGED WITH SAID L-SHAPED MEMBER ADJACENT SAID SPUR AND ENGAGED WITH SAID SHORT ELEMENT ADJACENT THE FREE END THEREOF FOR HOLDING A FOOT SNUGLY ADJACENT SAID SHORT ELEMENT; 